Carburetor



.1.1. TRACY AND L. H. MORSE.

CARBUHETOR.

APPLxcATloN FILED MAR, 8. 191e.

Patented 0013. 3l, 1922...

2 SHEETS-SHEET l.

TTQfe/mm.

J. J. TRACY AND L. H. MORSE.

CARBURETOR. APPLICATION FILED MAR. 8,1918.

Patented Unt. 31, 1922.

Uufrl) STATE-s PATENT FFICE.

JAMES J'. TRACY AND LAWRENCE H. MORSE, OF CLEVELAND, OHIO; SAID MORSEASSIGNOR T0 SAID TRACY.

CARBURETOR.

Application led March 8, 1918. Serial N0. 221,108.

To all whom t may camera.'

Be it known that we, JAMES J. TRACY and LAWRENCE H. MORSE, citizens ofthe United States, and residents of Cleveland, countyof Cuyahoga, Stateof Ohio, have jointly 1nvented a new and useful Improvement inCarburetors, of whichv the following is a specification, the principleof the invention being herein explained and the best mode in which wehave. contemplated applying that principle, so 'as to distinguish itfrom other inventions.

The present invention has as its object the provision of a carburetor,in which the character of the charge, or mixture, is properlycont-rolled to meet variations in the temperature of the air as it isdrawn into the carburetor. A further object is to provide for themaintenance of a uniform temperature in such air under normal operatingconditions. In other words, the rst feature of control functions lduringthe starting stage when only relatively cold air is available, but undernormal operating conditions, it is contemplated that pre-heated air willbe available and that by cont-rolling the temperature of such air, thesetting of the carburetor parts for varying the mixture will remainpractically constant.

To the accomplishment of the foregoingr and related ends, saidinvention, then, consists of the means hereinafter fully described andparticularly pointed out in the claims, the annexed drawings and thefollowing description setting forth in detail certain mechanismembodying the invention, such disclosed means constituting, however` butseveral of the various mechanical forms in which the principle of theinvention may be used.

ln said annexed drawings:

Fig. 1 is a vertical sectional central view of one form of thecarburetor embodying our present improvements; Fig. 2 is a vertif, calsection of a portion of said carburetor taken at right angles to the.plane of Fig. l as indicated by the line 2-2 thereon; Fig. 3 is ahorizontal sectional view of the same device with the indicated by theis a vertical sectional central view similar to that of Fig. 1, butillustrating a modified. form of construction; and Fig. 5 is a sec line3 3, Fig. 1; Fig. 4

plane vof the section beingl tional view of a detail of the lattershowing parts in different operative positions.

The carburetor, in connection with which our present improvements areshown in the aforesaid drawings, belongs to that type wherein the airfriction, or flow of air drawn through the device by the suction oftheengine, is relied upon to open and regulate not only such flow of air,butalso the flow of the hydrocarbon fuel which is mixed therewith toform the charge proper. More specifically still, the construction of thecarburetor, proper, in both the modied forms of the present invention issubstantially the same as that described and claimed in our co-pendingapplication, filed June 30, 1916, Serial No. 106,777, Ie-iiled April 8,1918, Serial No. 227,400. Accordingly, so far as similar parts occur inFigs. 1 and 4, sluch parts will be designated .by like numera s.

Referring first of all to the construction illustrated in Figs. 1 to 3,inclusive, the body of the device will be seen to consist of a tubularcasing 1 provided with an air inlet. opening 2 and an outlet opening 3.Such outlet opening is, of course, connected to the engine manifold, asneed not be further explained, and is controlled by a throttle in theform of a butterfly valve 4 of usual construction, carried by anoscillatory shaft 5 transversely mounted in such outlet opening andprovided with suitable operating means (not shown). The inlet opening 2is designed to be connected with a suitable heating arrangement (notshown wherein the exhaust gases from the engine or other heat source areutilized as the heating agent, as need not be explained in detail.

Rising centrally from the bottom of the casing 1 is a fuel-supply ductor nozzle 10, in the upper part of which is fitted a 'nozzle proper 11,that has enlarged head 12 of a diameter substantially equal to theexternal diameter ofsaid duct. The upper portion in hand as leading froma float-chamber 16, wherein the height of the liquid fuel is controlledby means of a float 17, as will be readily understood.

Surrounding the end of the nozzle l1, so as to be freely slidablethereon, is an annular valve 25 that serves to partially ll the annularspace between the duct and the surrounding casing Wall. This valve isadapted to be raised from its normal position (somewhat lower thanillustrated in Fig. l) to the position thus illustrated, or to a higherposition, by

means of a rocker 26 mounted in the lower portion of the casing and toone side ofl said nozzle 10, said rocker being connected to said valveby a. link 27. This rocker is carried by a transverse. shaft 28, one endof Which projects without the easing, and is provided with a lever 29and link 30 for the purpose o f manually 'controlling the setting ofsaid valve 25, in a fashion that Will be hereinafter fully described.

Centrally disposed in the upper portion of the casing 1, being heldthere by means of radial arms 31, is a cylindrical chamber 32 thatserves as a dash-pot to receive the upper piston-like projection 33 ofa. second annular valve 34, which, in t-he normal position of the valveillustrated in Fig. 1` surrounds the first-named annular valve 25, andsubstantially shuts off communication between the upper and lowerportions of the casing. A predetermined vertical movement of this valve34, however, will leave an annular opening, aswill be obvious, the sizeof such opening increasing as the valve continues its upward movement,while the point at which the opening first occurs, depends upon thesetting of the annular valve'25. The pistonlike portion 33 is spacedfrom the valve propel', and at the same time attached thereto, by meansof radial arms 35, between which the air is free to pass when the valveis raised, as just described.

Centrally mounted in the piston portion 33 of the annular air valve 3lis vet another valve 38, which controls the opening in the fuel-supplynozzle 11. The body of this valve 38 is coned on its under side to titthe beveled discharge orifice 18 'in nozzle 12, and

-is further provided with a relatively adjustable spindle orneedle-valve extension 39 threaded in said body and adapted to pro--ject within the bore 14 of the nozzle, such extension being tapered. asshown in Fig. 1. This fuel valve is not rigidly mounted in the pistonportion of valve 34, but is vertically reciprocable relatively thereto,a spring 40 serving to maintain it in normal posit-ion. but allowing itto have a certain amount of play, in order to insure that it willproperly center itself in the nozzle.

In addition to the means, including` thc lever 29 and link 30 connectedwith the rockduct l() and the ,upperv shaft 28 for manually positioningor settingr` the inner annular valve 25 that surrounds the nozzle, weprovide a. thermostatic device that is adapted to modify such settingras the temperat-ure of the air drawn into the easing 1 varies.

1n the form illustrated in Figs. 1 to 2), this device consists of ashort corrugated tube 45 filled with a suitable Huid, so as to elongateaxially as the temperature rises and shorten as the temperature falls.One end of this element is fixedly attached to the side Wall of thecasing 1, while the other end is connected to a second rocker 4G looselymounted on the shaft. This rocker 46 is in the form of `a yoke that isadapted to engage with an extension 47 of the rocker 26. Normally theweigl'it of the valve 25 which may be supplemented by a suitable. springif desired will be sufficient to maintain said rocker 26 thus inengagement with said lvoke` the result being that, as the thermostaticelement expands, the yoke turns toward the right, as shown in Fig. 1,and the valve 25 will gradually drop, or assume a lower and lowerposition, with respect to the supplyfuel nozzle.

The manual raising of the valve 25. in order to provide the necessaryrich mixture on starting up the engine, is, of course, in no wiseinterfered with by the presence of this tliermostatic controllingelement and the. operation'just described, lult as soon as thcrock-shaft 28 is left free, the position of the' valve 25 is determinedby such thcrmostatic device.

As has been previously explained. when a temperature is reached 'wherecomplete vapor-ization of the liquid fuel results. it is desirable tomaintain the temperature of the air supplied to the carburetor at a.constant point. Ye accordingly provide a` supplemental air inlet opening5() in the lcasing l. such opening communicating directly with theatmosphere, or, in other words, having no connection with anyheatingapparatus as has the main inlet opening 2. This supplcmental air inletopening is normally closed -by a suitable valve 51. but is adapted to beopened, when the temperature of theI air drawn into the casing reaches apredetermined point, by means of a second thermostatic element 52similar to the one just described, such element having a lost motionconnection with the valve, so as to lift it from its seat only after ithas expanded a certain amount.

The general operation of the device as now described in full should bereadily understood. Normally, the outer annular airvalve 34 will be inthe position shown `in Fig. 1. In order to start, the inner valve 25will be manually raised to a point somewhat higher than indicated insaid figure, the effect of cranking the engine being to raise the outervalve by the suction induced until it clears the inner valve. rlhe fuelsupply valve 38 will be raised correspondingly high and thus provide arich mixture, as is desirable in starting. As soon, however, as theengine is started and the manual control released, the inner valve 25drops until the extension 47 on the rocker 26 engages with thethermostatically controlled yoke 46. The outer valve 34, together withthe fuel valve, will dro a corresponding amount, andas the air rawn intothe inlet opening 2 becomes heated, the thermostatic element 45 willallow the valves in question to drop still lower, correspondinglyreducing the roportion of fuel tothe volume of air eingdrawn in. Whenthe temperature of such air reaches the desired point, its furf therrise will be checked by the action of the second thermostatic element 52in raising the valve 51 from its seat, so as to open the supplementalair inlet opening 50. Upon this device becoming thus operative, therewill, under normal conditions, be no further action on the part of thefirst thermostatic device; the sett-ing of the inner annular valve, inother words, remains fixed under such condition.

lt will be noted that, as shown in Figs. 1 and 4, only a slight space isleft'between the two annular valves to provide an easy working fit; alsothat the upper portion of the bore of the inner annular valve isenlarged so as to leave an annular space 53 between the same and thefuel-supply duct and nozzle, this space 53 being connected by means of aseries of apertures 54 with the lower portion of the casing. v

In the modified construct-ion illustrated in Fig. 4, the constructionand operation of the carburetor proper is substantiallv identical withthat just described, except that instead of utilizing a float chamber tomaintain the fuel at a predetermined level in thenozzle, we hereillustrate the use of a direct connection 55 with the source of fuelsupply, the admission of the fuel into the nozzle being controlled by aweighted valve in the form of a plunger 56, that has its lower end conedto conform with an upwardly facing seat 57 in the lower end of thenozzle.

rllhe connections, however, between the manually operable rock-shaft 28and the inner annular valve 25 are of different construction from thatpreviously described, in order to utilize a thermostatic element of adifferent form, viz, a. strip of' so-called thermostatic metal insteadof a hollow corrugated tube. As known in the art, such thermostaticmetal is a composite bi-me tallic article made up of two metals ofrelatively diiferent co-eificients of expansion, these being securelyunited to form mechanically a metallic strip or b-ar. Assuming that sucha.bar is approximately straight at a normal temperature, a rise intemperature will cause the same to bend in a predetermined direction,the amount of the bending being proportionate to the change intemperature.

Accordingly, instead of directly connecting the valve 25 by means oflinks to a rocker on the shaft 28, in the construction in hand we extendsuch rocker 60 in the opposite direction, and rigidly attach to theouter end of the same one end of a bar 61 ot' such thermostatic metal,the layer having thel higher co-efficient of expansion being disposedupwardly. -The upper end of this bar is then connected by short links 62with thel valve in question. It being understood that the bar issuiiiciently rigid, so as not to flex appreciably other than under theinfluence of a change in temperature, it .will follow'that manualsetting of the valve may be hadr just as in the other construction.However, upon releasing the manual control and the rock-shaft coming toa position of rest against a stop 63 (for example) any change in thetemperature of the incoming air will cause the thermostat-ic bar to benor bow in the fashion indicate-d in Fig. 5, so as to cause its inner endto occupy a relatively lower position and thereby corresoondingly tolower the inner annular valve. Should the air, on the contrary, growcolder, the bar will bend in the opposite direction so as to raise theannular valve.

This same type of thermostatic element may be utilized to admit asupplemental supply of coldair, in order to prevent. the temperature ofthe air as mixedk with the fuel from rising too high. As illustrated inFig. 4. a pair of oppositely disposed supplemental air inlet openings 65are formed in the casing adjacent the main air inlet opening 2, throughwhich pre-heated air is designed to be drawn, and a pair ofcorrespondingly facing valves 66, mounted on a com- Inon stem 67, areprovided to close these openings. balanced e'ect is obviously secured,the stem 67 being guided in a suitable bearing 68 formed in abar-extending transversely of the casing.- Rigidly attached at one endto the side wall of the casing is a thermostatic bar 69 of the same sortas the one previously described, the other end of such bar beingprovided with a fork 70, or otherwise'formed to engage a pin 71 in thestem of the valve, and thereby raise the lat-l ter whenever the airreaches a predetermined temperature. lln this way, a certain amount ofcolder air is admitted and the mixture maintained approximately at auniform temperature during the further operation of the engine.

As previously indicated, the temperature which it is desirable thus tomaintain con'- stant. is that at which complete vaporization of the fueloccurs, there being a loss in going to makeup the mixture should beyvdifferently proportioned, that is, the setting of the valve 25 underthe action of the ther- ,mostat must now be different from thatpreviously required.' We have found, in other words, that the action ofthe thermostatic element 61 must be checked, once such a temperature isreached. More specifically, if the mixture is not to be rarified to toogreat an extent, the action of such thermostat must be reducedapproximately one-half. This result is' very simply secured in theconstruction under consideration by providing a projection midwaybetween the ends of the rocker 60 wherewith the thermostatic element 61contacts, when it is bent or bowed a predetermined amount, correspondingwith the critical temperature. This projection conveniently takes theform of a set screw 72, so that adjustment may be had in thisparticular. y

Otherwise than as just indicated, the general mode of operation of thismodified form is the same as the one first described above.

Other modes of applying the principle of our invention may be employedinstead of the ones explained, change being made as regards themechanism herein disclosed, provided the" means stated by any of thefollowing claims or the equivalent of such stated means be employed.

However, if

We therefore particularly point out and distinctly claim as ourinvention 1. `In a charge-forming device, the combination of a suitablecasing having an outlet for the charge and an-air-inlet; a frel nozzledischarging within said casing; two valves co-operating to substantiallyclose the passage through said casing, one of said valves being adaptedto be moved by the suction of the engine; a thermostat mounted in theair inlet portion of said casing and arranged to be affected by thetemperature of the air admitted to said casing and adapted to operatethe other of said valves;v and' a. third valve, operated by saidsuction-actuated valve, for controlling the supply of fuel to saidnozzle.

2. In a charge-forming device, the combination of a suitable casinghaving an outlet for the charge and an air-inlet; a fuel nozzledischarglng' within said casing; two valves co-operating tosubstantially close the passage through said casing, one of said valvesbeing adapted to be moved by the suction ofthe engine; a thermostatmounted in the air inlet portion of said casing and arranged to beaffected by the temperature of the air admitted to said casing and ,l

adapted to operate the other of said valves; external means foroperating said other valve independently of said thermostat; and a thirdvalve, operated by said suction-actuated valve, for controlling thesupply of fuel to said nozzle.

Signed by us, this 6th day of March, 1918.

JAMES J. TRACY. LAWRENCE H. MORSE.

